Elastic friction clutch



Jan. 2l, 1930. F. G. JACOBS ET' AL 1574463-7 ELASTIC FRICTION CLUTCH Filed May 15. 11925 Patented Jan. 2 1, 1930 UNITED STATES maar? PATENT 'oFFICE- FRANCISCUS GERARDUS .T ACOBS, 0F ROTTEDAM, AND JOHA1=MRTINUS MARIA SCHMITZ, OF HILLEGERSBERG, NEAR BTOTTERDAM, NETHERLANDS l ELASTIC FRICTION CLUTCH.

y Application led May' 15, 1925, Serial No. 30,586, and in the Netherlands January '12, 192.5.

From the Dutch Patent Nr. 2,236 cl. 47 c. 13 a disengageable friction clutch is known in which` the friction blocks are pressed down .by centrifugal force and by spring pressure direct-ion, because when rotating in one of the Y twodirections itacts as a ratchet and pawl device. Furthermore it has appeared in practice that in the same installation 1t. does not always yield the same H. P. Moreover,

in case of an overloading by the driven tools i the rotation speed of the engine and clutch with the driven shaft and tools is retarded. Furthermore in disengaged position the spring pressure is greater than in engaged position.

The invention relates to a clutch device of the above described type which does not have these drawbacks, which fully automatically engages and disengages and which moreover restricts the transmission of shocks and the influence of the inertia effect, between certain limits. I

According tothe invention the capacity is restricted between a minimum and a maximum couple in which the minimum couple is caused by spring pressure or .by elasticity, and theV maximum couple by spring pressure or. elasticity augmented by the pressurek caused by the centrifugal forceof the friction blocks or of special masses. A

According to .the invention the friction blocks may further be so arranged that by theincrease or decrease of the centrifugal force they are radially moved.

Furthermore the invention enables the clutch to be combined vwith an Ordinar centrifugal clutch in order to start under oad a mtor without startingmoment, for instance a combustion engine ora monophase alternating current motor.

A Finally the invention enables the clutclitdbe combined with a ily wheel arranged on the driven shaft.

Some embodiments of the invention will 'other side.

now be further explained with reference tothe accompanying drawings.v

The Figs. 1 and 2 respectively are` a diagrammatical cross-sectionl and' longitudinal section of the clutch according. to the linvention.

Figa 3 is a longitudinal section of the comi bination witha centrifugal clutch for starting a motor without starting moment, certain detailsl of construction being omitted.

Fig. 4 is a longitudinal section of the combination with a fly wheel arranged on the driven shaft. h

Fig. 5 is a cross section taken along the line 5--5 of Fig. 3. Y

I In the Figs. 1 and 2, 1 is the' driving drum which is connected with the. motor. -The driven part of theclutch consists of the yoke 2 with the friction blocks 3. These blocks 3 are permanently pressed against the drum l by springs 4 which are arranged in suitable places. These springs 4 cause lthestarting moment 'which must so bejchosen that when rotating the driving part, the driven part will also rotate.

If the driven part is rotating the blocks or special masses intendedfor this will cause l amount as the couple of the elastic clutch. Inr case of shocks on the side of the driven partQ the retardations andaccelerations caused by between the in i this and also the inertia effect on the source" I of energy duringv'working which is a consequenceof this, as well as the torsional oscilla-` tions and vibrations' are restrictedbetwen certain limits namely the4 largest couple'on theone side andthe starting moment on 'thex I VithinY these limits the redress itself after Adecrease of the resistance.

"couple `is always redressed automatically. If the resistance of the driven `part becomes as ,large or .largerl .than the largest couple, in which case without to a value Within the admissible limit. During the time in Which the value of the resistance is above this limit the value of the couple is atl the utmost equal to that of the starting moment.-

e The springs 4 must be so arranged that they move the blocks 3 radially.

Experiment-s have proved that the applica- -tion of a c l'utch constructed according to the invention will cause considerable saving in comparison with the clutch such as is described in the above mentioned Dutch Patent Nr. 2,236 and still more with regard to other:

4au centrifugal clutch.

--shaft and 8 the driven tool. .shaft 7 is provided with a casing 9 keyed By means of the clutch according to the invention it is possible to start under load a motor Without starting moment, for example a combustion motor or a monophase alternat- 'ing current motor even under full load.

This-is done by combination with an ordinary An embodiment of this` is given in Fig. 3 in section. In this figure, 7 is the driving The driving -to shaft' 7, and in which an ordinary centi-it- 1 6 in its turnstarts the driven .tool 8.

` higher number of revolutions ugal clutch 5, including a casing 5 loose on shaft 7, and4connectible thereto by centrifugal clutch action, is arranged.` This casing 5 cooperates with a clutch 6 constructed ac- ,cording to the invention as described in counection with Figs. l and 2 and which clutch principal consequence of the application of lthis combinationvis that a certain percentage or' the turning couple is obtained only at a 1 if no clutch 5 Were used.

.10ct a` cl'utchasin Figs.l l and 2l is' keyed.

In orderto extend thelimits between the minimum and the maximum couple a 'Hy per minute thany .Witlrthe'highest couple., The couple dea coupling member freely picks up rotation through the spring' tric-"` tional engagement betiveei said coupling and radially movable members and afentrifuf gally movable' clutch element to said driving part and engageable Witlif'saidcoupli'ng member.l Y i 2. In a clutch, a coupling member rotatably mounted' on the driving part; and having two o lfs'etportions providing two substantially concentric rings, radially slidable members mounted en the l driven part,`spriiigs normally holding said yslidable members in contactvwitli the inner surface of the innermost ring, a second coupling member mounted fast on the driving part to rotate. therewith, arid-equipped with` clutch means operable to bemov'ed into con tact with the under surface of said outer concentric ring. v

In testimony -whereof` We alix our signatures. A

JOHAN MARTINUS MARIA SCHMITZ. FRANCISCUS GERARDUS JACOBS.

ivlieei may b e arranged on the driven shaft. Such a fly Wheel may also be employed for utilizing the kinetic energy obtained between 'the minimum and the maximum couple for ,obtaining or increasing kinetic energy With,

out the supply of power exceeding the maximum couple.

. In Fig'. 4 a longitudinal section of an embodiment is given in which a'ly -`zvlieel is-arrangedon the driven shaft. In this ligure, 7'is4 the drivin-g shaft and .8 the drivensliaft. On the driving shaft 7 the. 'casing or drum ...Incasing 10 is located a clutch constructed ally Wheel 12 is y shaft 8.

according to Figs. `land 2, andiin addition arrahgedon the driven Such adevice may for instance beapplied dri-ving and driven parts,

, with a source of-pow'er Witfh :it-high full load (ouple. Under ordinary circumstances the source of power cannot; yield the highest couple Without soon'occurring damages such .as melting of fuses. .The'applieation of the i device accordingto Fig. 4 no w enables .one '..to load the source of powerv in'termittin'gly 

